A generalized fault simulator for combinational logic circuits

A generalized approach to the design of fault simulator using a library of simulation primitives is presented in this paper. A comprehensive set of simulation primitives has been developed using C programming language on the IBM PC. This library of simulation primitives has been used in realizing a fault simulator for automatic test pattern generation in combinational logic circuits. The fault simulator employs a combination of random pattern generation, concurrent fault simulation and the FAN algorithm for generating the complete set of test vectors to cover all the faults in the fault dictionary of the circuit under test. The library of simulation primitives is general enough to facilitate the development of fault simulators using any other test algorithms such as DALG or PODEM.     

Concise vector equations for stereopsis

The vector formulae for computing the spatial coordinates of a point from matched images are derived using a simple procedure, yielding compact expressions suitable for a vector co-processor. The relationship between accuracy of depth computation and image-matching algorithm parameters is also discussed.     

Growth of praseodymium tartrate crystals in silica gel

The growth of praseodymium tartrate crystals in the system Pr(NO₃)₃-Na₂ SiO₃-C₄H₆O₆, using a single-tube-single-gel technique is described. The growth conditions are delineated and a spherulitic morphology is reported. The spikes attached to the spherulites are single crystals of praseodymium tartrate. The mechanisms of crystallization for various types of spherulites are described. The information presented contributes to the understanding of spherulitic growth in general, and that of praseodymium tartrate in particular.     

Optical microscopic studies on grown and etched surfaces of flux grown LaAlO3 crystals

Surface structures on as-obtained flux-grown crystals of LaAlO₃ have been investigated. Strictly oriented square, circular and rhombus shaped pointed, as well as flat-bottomed etch pits are observed. Etch pits along lineage boundaries, intersecting low-angle tilt boundaries and helical dislocations are illustrated and described. Different orientation of etch pits reveal twinning in LaAlO₃ crystals. Microdisc patterns and flux inclusions are also observed. The etch patterns on the as-obtained LaAlO₃ crystals are explained to be as a result of the flux cleaning operation of crystals in HNO₃. Experiments on etching established HNO₃ to be a dislocation etchant for LaAlO₃ crystals. Dislocation etching kinetics of the HNO₃-LaAlO₃ surface system are investigated for the freshly identified sites as well as for sites having a previous history of etching. Data obtained on the effects of etching time, etchant concentration and temperature on the dislocation etch rates, are analysed. The results obtained are presented and discussed.     

Effect of high fat diets with and without cholesterol on erythrocyte and tissue fatty acids in rats

Male weanling wistar rats were fed synthetic diets containing 20% safflower oil (SFO) or palm oil (PO) with and without cholesterol for a period of six weeks. Erythrocyte membranes were isolated and their fatty acid composition were determined at the end of the experiment. Besides the fatty acid composition of the kidney and spleen lipids were also determined. Erythrocyte membrane, kidney fatty acids of rats fed safflower oil (SFO) had in the majority of variants a higher level of n-6 fatty acids when compared to palm oil group. However, in the spleen, the level of n-6 fatty acids in the palm oil groups were higher than in the safflower oil group. In general the arachidonic acid [20:4 (n-6)] levels were higher in the spleen and erythrocytes particularly in the cholesterol fed groups when compared to the kidney levels. Palm oil fed rats had a higher level of palmitic (16:0) and oleic [18:1 (n-9)] acids. Rats fed diets containing cholesterol significantly reduced the level of stearic (18:0) but increased the level of oleic [18:1 (n-9)]. linoleic [18:2 (n-3)], and arachidonic acids [20:4 (n-6)]. The ratios such as 18:1 (n-9)/18:2 (n-6), 18:1 (n-9)/18:0, 18:2 (n-6)/20:4 (n-6) and 20:4 (n-6)/18:2 (n-6) are all indicative of the normal activity of enzymes involved in the desaturation and elongation. Thus these studies indicate that addition of cholesterol can modify the fatty acid composition in erythrocytes, kidney and spleen lipids.     

Estimating errors of certain Gauss quadrature formulae

Using Cauchy's integral formula (as in [8]) we obtain the closed form error-estimates for the general Gauss-Chebyshev quadrature formulas. Some of the estimates of the errors of these quaratdures are excellent in the sense of Chawla [3].     

Assessment of the development and implementation of tools in contract cleaning

This paper illustrates and discusses problems with the implementation and use of ergonomic tools and techniques in the process of cleaning. Cleaning is an occupation with a high risk of developing work-related disorders. One high-strain task where recommended tools and techniques are difficult to apply is cleaning staircases. This study evaluated the muscular activity of cleaners while mopping staircases using two different mop handles and found that an easily adjustable mop handle can decrease a cleaner's physical load. The results also show that the implementation and contextualization of the mop are of great importance for how a mop is used. A more holistic approach is needed to improve the benefits of good tools and techniques in cleaning work. More research is needed on how workplace organization can be improved to support the implementation of strategies to increase the health of professional cleaners.     

Parallel cryptographic hashing: Developments in the last 25 years

Abstract

Parallel computing has led to fundamental changes in almost all research areas associated with computer science; cryptography is no exception. Besides improved speed and resource utilization, parallel cryptography is also promising from the security point of view. In particular, cryptographic hash functions (CHFs) – “the swiss knife” of the cryptography toolkit – stand to gain a lot from parallelism. Consequently, there has been an increasing interest in research towards the development of parallel CHFs for faster, more secure and more efficient hashing, particularly since the competition for the SHA-3 standard. This paper attempts to consolidate the research efforts in the field of parallel hashing, exploring various approaches in this direction. Within each approach discussed in the article, CHFs have been classified on the basis of construction and their design, implementation and performance have been explained, with the primary focus on parallelism. Finally, a broad temporal overview of the developments in the field of parallel hashing has been presented.